Federal Weight Loss Study

A new federal study suggests counting calories is the most effective way to lose weight.

Researchers followed more than 800 overweight adults on different diets for two years.

Though the diets were a twist on commercial plans, the study did not directly compare popular diets.

Reduction in weight and waist size were similar among all diets.

However, participants had trouble sticking to a single plan and weight loss was modest for most.